Dairy wax composition



United States Patent Office 3,098,598 DAIRY WAX COMPOSITION George A.Weisgerber, Cranford, and Arthur J. Reinsch,

Middletown, NJ., assignors to Esso Research and Engmeering Company, acorporation of Delaware N Drawing. Filed June 1, 1061, Ser. No. 114,0048 Claims. (Cl. 229--3.1)

The present invention is concerned with a new and improved waxcomposition and more particularly relates to the use of such acomposition in the coating of paperboard milk cartons and the like. Inaccordance with the present invention, a superior dairy wax compositionis formulated without utilizing residual microwaxes and using highquality waves secured from distillates. By utilizing the waxes of thischaracter, greater flexibility and better wax distribution is secured,thereby producing a high quality waxed container. The wax composition ofthe present invention is secured by utilizing a conventional refinedparaffin wax in conjunction with critical quantities of particularmicrocrystalline waxes which have been pro duced from variousdistillates.

In the refining of hydrocarbon oils such as petroleum oils, it is knownto segregate paraffin waxes from socalled paraffin distillates, waxylubes and the like. The overhead or paraffin distillate cfraction forexample has a boiling range of about 580 F. to 850 F. and a viscosity ofabout 80 S.U.S. at 100 F. A heavy lubricating oil distillate sidestream, for example, has a boiling range of about 800 F. to 1000 F. anda viscosity of about 50-70 S.U.S. at 210 F. The residuum comprises allthe hydrocarbons boiling above this range and, for example, has aviscosity from about 150 to 200 S.U.S. at 210 F. Crystalline or parafiinwaxes produced from the paraffin distillates have melting points whichrange rfrom about 120 F. to 150 F. This type of wax is characterized bylarge well-formed crystals that can be readily separated from the oil.Furthermore, this type of wax generally contains a relatively smallamount of oil and can be refined with comparative case.

The segregation of these waxes is secured by a number of processes. Forexample, it is known to chill the selected wax containing fraction inorder to secure crystallization of the wax and to remove the waxcrystals from the oil by filtering, centrifuging and the like. It isalso known to use various dewaxing solvents such as liquid normallygaseous hydrocarbons, such as propane, as well as other solvents, suchas methyl ethyl ketone, methyl isobutyl ketone, and the like. It is alsoknown to utilize in dewaxing operations solvent mixtures wherein onesolvent comprises a wax precipitating solvent while the other comprisesa solvent having a high solubility for oil. A solvent mixture of thischaracter, for example, comprises 40% by volume of toluene and 60% byvolume of methyl ethyl ketone In utilizing a mixture of this character,it has been thepractice to add the mixture in toto or incrementally tothe waxy distillate as it is being chilled. In dewaxing operations, itis also known to use various filter aids and other agents in order torender the dewaxing and filtering operations more eflicient.

The wax segregated from the hydrocarbon oil, usually termed slack wax,contains from about 10% to 40% of oil. The slack wax is refined usuallyby conventional sweating to produce crude scale wax in a manner toreduce the oil content to less than about by weight. The slack wax maybe distilled to obtain the desired boiling mange wax prior to sweating,if desired. This crude scale wax generally has an oil content of about2% to 3% by weight. In order to remove this oil from the scale wax toproduce a refined wax, such as a refined paraliin, having an oil contentbelow about .5 usually below about 3%, various procedures have beenproposed and employed.

Alternatively, the slack wax may be processed by a solvent deoilingprocess, to remove oil from the wax. In this, the wax is dissolved insuch solvents as methyl isobutyl ketone, methyl ethyl ketonc, ormixtures of methyl ethyl ketone and toluene in a ratio of approximatelyto 25, respectively. The wax solution is cooled to producecrystallization and the crystallized wax is removed by a process such asfiltration. The filter cake of crystallized wax may be washed with coldsolvent to remove occluded oil solution. The wax so produced may be anunfinished refined paraffin wax or an unfinished microcrystalline wax,depending on the nature of the slack wax feed, and on the selection ofcrystallization conditions. After oil removal from the wax, it issubjected to a finish ing process such as clay percolation orhydrofining. In the latter, the process involves treating the unfinishedwax with hydrogen gas at a rate of about 0.5-1.0 volume of wax per hour,at 500-800 p.s.i., at 500-600 F., in contact with cobalt molybdatecatalyst. Or, at lower pressures such as 200 p.s.i., a nickel catalystmay be used. The hydrogen treated wax product is greatly improved withrespect to color, odor and purity.

It is also known in the art to segregate microcrystalline waxes fromresidual oils. As pointed out heretofore, these crystalline waxes arenormally produced from residuums which boil above about 1000 F. and haveviseosities in the range from 150 to 200 S.U.S. at 210 F. Thesemicrocrystalline waxes are characterized by very minute crystallineforms and which melt in the range from about 145 -F. to 190 F. Thesemicrocrystalline waxes from residual oils are of a relatively highmelting point and of different crystalline structure. Themicrocrystalline waxes may be prepared from any of the paraffin or mixedbase crude oils. The undistilled residue may be treated with sulfuricacid and neutralized to remove the tarry matter and unsaturatedhydrocarbons. The undistilled residue also may be deasphalted. Thetreated stock, containing a fairly high percentage of wax, as evidencedby a very high pour point, may be dewaxed by blending with a dewaxingsolvent, such as propane, methyl ethyl ketonebenzol, or petroleumnaphtha and chilled, and filtered or centrifuged to separate the Waxyfraction from the residual lubricating oil solution.

This dewaxing operation produces a wax fraction containing some oil andsolvent. The wax after removal of the solvent has 13. melting point offrom about to 180 F. The wax may be again put in solution with moresolvent or naphtha and chilled and filtered or recentrif-uged to furtherreduce the oil content. The wax which separates in either of theseoperations is referred to as crude microcrystalline wax. The waxseparated in the second crystallization process afiter stripping toremove solvent is fairly dry and of a low oil content. This wax shouldnot be confused with petroleum jellies which contain large amounts oroil. The crude microcrystalline wax may be again put into solution withnaphtha and filtered thnough clay or an equivalent material in order toimprove its color. The clay filtered solution is distilled to remove thenaphtha, the residue being a refined petrolatum wax having a meltingpoint within the range of about to F. Alternatively, themicrocrystalline wax may be hydrogen treated to improve its color andodor, such as by hydrofining at about 600 F., 600 p.s.i. of hydrogen,using cobalt molybdate catalyst. The source of the crude oil and the oilcontent or the refined microcrystalline prodnot will affect the meltingpoint of the final wax product. The refined microcrystalline wax,sometimes called amorphlous wax, is as pointed out, of a very smallcrystal structure.

It is also known in the art to segregate microcrystalline Patented July23, 1963 waxes from distillate lubricating oils. These distillate typemicnocrystalline waxes differ in characteristics from the residual typemicnocrystalline waxes hereinbefore described. Thus, the distillatewaxes are lower in viscosity and are generally finished to a higherdegree of purity, such as freedom from color and odor. Furthermore, thedistillate microorystalline waxes have two advantages over the residualmicrocrystalline waxes from the standpoint of ease of manufacture.Namely, first, the distillable nature of the wax makes it possible tomanufacture specific microcrystalline wax fractions for use in specificproduct applications; and, second, the distillate waxes can be morereadily and more economically refined with respect to color and odorthan can the residual microcrystalline waxes. These features ofdistillate microcrystalline wax (low viscosity, high purity, selectfractionation, economy of finishing) have been found to be of particularvalue in the present invention.

The distillate microcrystalline waxes are manufactured fnom distilledwaxy lubricating oil fractions from crude oil. These fractions will varywith regard to distillation range, depending upon the desired viscositygrade of the lubricating oil ultimately produced. Thus, a number offractional cuts may be taken across the lubricating oil distillationrange, to produce different lubes. The entire range may cover 'adistillation from about 6S01180 F. (760 mm. basis). Each of thefractional waxy lubricating oil cuts is processed to remove the waxycomponents by a process such as dewaxing by solvent crystallization. Ashereinbefiore described, this comprises dissolving the waxy distillatein such solvents as methyl ethyl ketone, methyl isobutyl ketone andmixtures of methyl ethyl ketone and toluene, cooling the solution tocause crystallization of the wax, then filtering to separate thelubricating oil and the slack Wax. The slack wax is then processed tofurther remove oil from it by a procedure such as solvent deoiling. Inthis operation, the excess oil is removed from the slack wax, by thesolvent crystallization technique, while, at the same time, the solventand temperature conditions are controlled to :achieve a fractionalcrystallization of the wax fraction. Thus, a slack wax may becrystallized first at a relatively high temperature to separate the mostcrystalline, paraffi-nic and high melting wax components present in theslack wax as the solid phase. The melting point may range from 140 to190 F depending on the properties of the slack wax feed and thecrystallization temperature. The filtrate phase is then further cooledto cause a second crystallization of the wax which is microcrystallinein nature, and of lower melting point than the first wax cut. Waxes inthis fraction vary from 125l40 F. melting point. By selection of thesolvent composition and crystallization temperature, the exactproperties of the separated wax can be controlled. The

filtrate from the second crystallization contains the oil which wasremoved from the wax fractions. Both the first and second fractions ofwax contain about 0.2 to 1.5% oil, this generally being 0.3 to 1.0% oil.These deoiled wlax fractions may then be finished to the desired degreeof purity with respect to color and odor by one of several methods, suchas the hydrogen treating (hydrofining) or adsorption (clay percolation)methods previously described. As a final manufacturing operation, theparaffin or microcrystalline wax may be distilled again to furtherseparate specific wax fractions.

In compositions of the current invention, it is particularly importantthat microcrystalline waxes of the distillate type rather thanmicrocrystalline waxes of the residual type, be employed as componentsin the dairy wax coating formulations.

It is also known in the art that the wax formulations used for milkcarton coating are among the most critical of all wax applications froma quality standpoint. The quality of the wax coating is under continuousclose scrutiny by the dairy operators, milk distributors, retail stores,and the ultimate users. For example, it is known that waxes exist on themarket which have good performance quality in one or two aspects, butwhich also have certain quality weaknesses. The overall quality fordairy waxes is controlled by a number of rigid tests. One test is theflaking test which measures the degree to which wax particles will flakeoff the canton and adulterate the milk. Other rigid tests for wax formilk coated cantons are the bottom wax accumulation test, the bottom waxflowing test, the cold flexibility test, the consumption test, as wellas the appearance of the coating, the dye coverage, and the rubaolf.

However, the most important diactors are those that concern the veryundesirable flaking, since the excessive wax floats in the milk and isof immediate deep concern to the users. Flaking is a prime cause ofcustomer complaint. The flaking test procedures are as follows for Waxedmilk cartons after passing through the waxing machine and after fillingwith a liquid at 38 F., the normal filling temperature.

METHOD A Five to ten filled test cartons are each dropped eight timesfrom a height of 7 inches onto a rail frame, i.e. a group of rods spacedapart, 4" long for /2 gallon cartons and 3 long for quart cartons. Thedisplaced flakes are filtered out, washed, dried and weighed.

METHOD B Same as Method A except that the cartons are dropped onto ametal plate slightly greater than the size of the carton bottom, havingthe corners of the plate turned up (dog-earred) to a height of A METHODC Thirty-six filled test cartons are each dropped twice from a height of5 inches onto the corner plate described in Method B for half gallons.For quarts, the 36 cartons are dropped 6 times from a height of 5inches.

The bottom wax accumulation test is a visual rating of the relativeamount of wax that has run down the sides of the carton and has gatheredinside of the carton at the bottom. The accumulation is rated as light,moderate, or heavy. Greater accumulation tends to lead to more flaking.

The bottom wax flowing test determines the amount of molten orsemi-molten wax that flows across the bottom of the carton due to thevigorous motion of the carton as it travels through the cooling or waxhardening section of the dairy machine. The molten lava-like flow doesnot re-fuse with the main body of wax, but tends to solidify separatelyfrom the main coating, in the form of a thin sliver or overlayer on thebottom, in the corners, or washed up the sides. This overlayer is veryreadily displaced if the carton receives a mechanical shock due to roughhandling. Flowing is a phenomenon depending very much on the machinetype, and on the routing of the carton within the cooling chamber. Insome machines flowing does not occur and is not contributory to flaking.In other machines, where flowing can occur, it becomes an extremelyserious problem. Flowing is evaluated by visual observation of theinside coating of the carton and the displaced flakes.

The cold flexibility test determines cold flexibility rather thanbrittleness. Cold flexibility is desired in the wax coatings in order toresist mechanical shock. The cold flexibility is evaluated by cuttingoff the bottom of a test carton which has been filled with liquid at 38F., and rapidly flexing the bottom through an angle of about degrees.The rating of poor to very good is made on the basis of audiblebrittleness, the degree of cracking and the separation of rupturedflakes from the bent paperboard.

Consumption is the rate of wax usage per thousand cartons, measured byweighing cartons before and after waxing. High wax consumption generallytends to produce high wax accumulation and flowing and high flaking.

Also, a reasonable amount of consumption must always be maintained inorder to achieve a uniform protective covering of the paperboard.

In accordance with the present invention, a conventional refinedparaflin wax is used in conjunction with 5 The microcrystalline waxesare secured from distillate critical amounts of various microcrystallinewaxes prolube oil petrolatums by recrystallization techniquesutilizduced from distillate sources. These waxes of the presing asolvent comprising methyl ethyl ketone and methyl ent invention haveoutstanding and unusual advantages isobutyl ketone. over othercommercial dairy waxes. The waxes of the Microcrystalline wax A wassecured by treating a dispresent invention avoid or minimize the bottomaccumutillate waxy lubricating oil stream of about SAE 30 with lationand flowing, and impart desirable cold flexibility, a solvent at atemperature of 20 F. with approximately leading to an overall reductionin the level of the flaking. 3 volumes of solvent to one volume of oil.Under these The wax of the present invention will also have betterconditions, a slack wax was produced and separated from performance byreason of better cold flexibility characthe lubricating oil. The slackwas then redissolved in teristics. about 6 volumes of solvent to onevolume of wax and Thus, avery important part of this invention is thatthese Cooled. to to achieve qystalli'zatiom Under these characteristicsare achieved Without utilizing residual conditlons, melting PaintParafi'in Wax Was microwax o overhead waxes are used Advantages removed.The filtrate was further cooled to a temperature are thereby realizedwith regard to purity, availability and of F with treatment 3 Volumes ofsolvent to one cost. While the residuals can be further purified, thisVolume of WaX, cfystalllze microcfystalline WaX has not been widelydone, and the added cost largely Microcrystalline wax B was secured bytreating a waxy excludes the resulting highly purified microcrystallinewax lubricating oil distillate of SAE 60 with 5 volumes of. from dairywax for the competitive market. Overheads solvent to one volume of waxylubricating oil distillate are inherently cleaner and are moresusceptible to conat a temperature of F. Under these conditions, aventional finishing methods. 25 slack wax was produced which was thenredissolved with Thus, the present invention comprises the use ofoverheat in about 6 volumes of solvent to one volume of wax head waxes,without residuals; the use of specially preplus oil feed and cooled toabout 96 F. The wax fraction pared, solvent crystallized overhead wax ofa relatively precipitated comprised crude microcrystalline wax B.flexible type, (the wax is prepared by deeper deoiling -i.e. Thefiltrate was further cooled with 7 volumes. of sollower temperature thanhas previously been used to make vent to one volume of wax plus oilfeed. At the temperadairy wax components); and the use of a special highture of 48 F., the crude microcrystalline wax 10 was congealing pointoverhead wax to reduce bottom accollected. cumulation and flowing. Thecrude microcrystalline waxes were finished by In cases where control ofaccumulation and flowing are hydrogen treating at 600 F. and 600 p.s.i.,using cobalt desired or necessary, it is seen further that thecongealing point of the preferred dairy wax should be about 140 F.minimum, and preferably about 145 F.

The refined paraffin wax is secured as described heretofore andcomprises a deoiled slack wax to produce a refined wax having an oilcontent less than about 3% by weight.

molybdate catalyst to improve their quality with respect to color,\odor, and purity. The inspections of the respective wax fractions arelisted in Table I; I

Table I TYPICAL WAX COMPONENT INSPECTIONS Identity Microcrystalline A BC Refined base wax Description Second crystalli- First crystalli- Secondcrystallization from zation from ration from Ketone (MIBK) MIBK deoilingMIBK deoiling deoiling of SAE of SAE slack of SAE 60 slack 30 slack waxwax wax Gongealing pt, F 1% 139 1 128. Viscosity at 210 F., cs 6.511.0... 11.4 3.8. Distillation, F. at-

Pressure 10 1 1 10.

5 an) am 610 502,

98 71 688 MR 62L Width of distillation at 595%, F 216 at 10 mm... 150 at1 mm 255 at 1 mm..." 135 at 10 mm.

The waxes of the present invention are characterized by having thefollowing constituents.

The high quality of the Wax composition of the present invention may bereadily appreciated by the following examples wherein the various w axcompositions were Percent by Weight 65 tested utilizing several fieldtests and full-scale machines.

Constituents Range Preferrcd Test location Machine model CriticalityRefined par'affin wax (about 3% oil) -90 F, quart Bottom waxaccumulation. Microcrystalline A 8-12 0, 36 gallon" Accumulation and floing, Microcrystalline 3.. 3-12 5 S. 3 gallon Accumulation.Microcrystalline C 3-7 5 Polyethylene (7,000 molecular Weight) 1-2.0 .5Polyethylene (12,000 molecular Weight) 1-2.0 .5 Oxidation inhibitor00031001 -0005 The results of these test are shown in the fOHQWlHg TableII.

Table II DAIRY WAX CONTAINING MIOROCYSTALLINE WAXES A, B, C IMPROVESFLEXIBILITY, REDUCES FLAKING AND ELIMINATES FL-OWING [Test arrangement:Location L, machine 0, wax temperature 180 F.]

Test I II III IV Base plus 0.57 12,000 molecular weight oomposltmnpolyethylene plus 0.5% 7,000 molecular weight polyethylene plusmicrocrystal- Cmpe line wax mive 4 B 7A 4 B 107A "7 B conimer' 17 A, ,ocia wax 03% O0 05% OD Consumption, lbs/1,000 otn 42.0 40.6 42.0.- 42.3.Flaking, gm./1,000 ctn.:

Method A 9 4 22. MethodB 2'; 17 10 24. Method 0 0.8 0.2 3.3.Co1dfiexibility Very good". Very good... Very good Good. Flowing YesVerylittle... Np Yes. Bottom wax accumulation Moderate--- Lt.tomod LightHeavy Oongealing point, F. 13 141 1 5.

From the above it is apparent that formulation I gives fairly goodperformance, similar to a highly rated commercial wax IV, but with thedisadvantage that bottom wax accumulation and flowing occur. This isvery markedly reduced by adding 3-5 of C, and the better waxdistribution directly reduces flaking, as measured by the several testtechniques. In this arrangement, where flowing is critical, the fullformulation with C is required.

I Additional tests were carried out with the following results.

From the above it is apparent that the improved wax V gives lessaccumulation, better flexibility, and less flaking. In this machine,flowing is not critical. However, even in the absence of flowing, wax Vis better than wax VI.

Additional tests were carried out in a machine where flowing was notcritical. From the examination of the following data, it is apparentthat wax C shows continued general advantage over two highly ratedcommercial waxes.

Table IV NEW DAIRY WAX IS SUPERIOR TO COMPETITIVE PRODUCTS [Testarrangement: Location D, machine S] Test No VII VIII IX Composition IIIIV Competitive commercial wax Consumption, lbs/1,000 ctn 48.7 48.9 55.3.Flaking, gin/1,000 0th.:

MethodA 9 0 22. MethodB 13 G6 18. Cold flexibility Good Poor.Bottomwaxflowing No No No. Bottom wax accumula Moderate- Heavy Heavy.

From the above it is apparent that, in still another machine whereflowing is not critical, the wax composition of the present inventionshows excellent advantages over two highly rated commercial waxes.

Thus, the presentinvention is concerned with an improved wax compositionwhich is particularly desirable for coating of dairy cartons whichcomprises a base parafiin wax used in conjunction with critical amountsof disrillate micnocrystalline waxes.

While the wax compositions of [the present invention were particularlydeveloped and designed to serve as coatings for milk cartons, it will beappreciated that these wax compositions will also find usefulapplication in other fields. Thus, paper or paperboard products coatedwith Waxes of the current'invention can be effectively used forpackaging of orange juice, grape juice, cottage cheese, frozen food, andthe like. In such applications, the excellent coven'ng quality of :thewax, its flexibility at low temperature, resistance to thermal ormechanical shock, good purity qualities and so forth, are of particularvalue. Similarly, the Wax may be used as a direct coating of foodstuffsor other items, without paper, where the packaged material is to besubjected to conditions of low temperature, mechanical shock, and thelike.

What is claimed is:

1. An improved wax coating composition which comprises essentially arefined paraflin wax present in a con- CGIHIFMIOH from about to byweight, a first overhead microcrystallline wax present in aconcentration of from about 8 i 12% by weight, said first overheadmicrocrystalline wax having a congealing point of about F., a 5%distillation temperature at 10 mm. pressure of about 490 F. and a 95%distillation temperature of about 706 F., a second overheadmicrocrystalline wax present in a concentration from about 3 to 12% byweight, said second overhead microcrystalline wax having a congealingpoint of about 182 F., a 5% distillation temperature at 1 pressure ofabout 509 F. and a 95% distillation temperature of about 659 F., and athird overhead microcrystalline wax present in a concentration of fromabout 3 to 7% by weight, said third overhead microcrystalline wax havinga congealing point of about 136 F., a 5% distillation temperature at 1mm. pressure of about 436 F. and a 95% distillation temperature of about661 F.

2. An improved wax covered canton which comprises in combination a papercarton having adhered thereto a wax composition as defined by claim 1.

3. The composition of claim 1 wherein said refined parafiin wax ispresent in aconcentration of about 79% by weight, wherein said firstoverhead microcrystalline wax is present in 'a concentration of about10% by weight, wherein said second overhead microcrystalline 9 waxpresent in a concentration of about 5% by weight, and wherein said thirdoverhead microcrystalline wax is present in a concentration of about 5%by weight.

4. The composition as defined by claim 3 wherein said compositioncomprises about 1% of polyethylene.

5. The composition as defined by claim 4 wherein said polyethylenecomprises about 0.5% by weight of a polyethylene of about 7,000molecular weight and about 0.5% by Weight of a polyethylene of about12,000 molecular weight.

6. The method of preparing improved wax coating compositions comprisingtreating a waxy lube distillate with solvent thereby precipitating a waxhaving a melting point of about 155160 F. and thereafter cooling thefiltnate to crystallize a first microcrystalline wax, treating a secondwaxy lube distillate with solvent to precipitate a slack wax therefromand thereafter deoiling said slack wax to produce a secondmlicrocrystalline wax, thereafter cooling the filtrate from the saidsecond microcrystalline wax to precipitate a third microcrystalline waxand then mixing minor amounts of the above first, second and thirdmicrocrystalline waxes with a major amount of a refined paraffin wax.

7. The method of claim 6 wherein an additional minor amount of apolyethylene is present.

8. The method of claim 6 wherein the first waxy lube distillate has anSAE viscosity of about 20 to 40 and the second waxy lube distillate hasan SAE viscosity of about References Cited in the file of this patentUNITED STATES PATENTS 2,733,225 Smith Ian. 31, 1956 15 2,967,817 Marpleet al. Jan. 10, 1961 2,988,528 Tench et a1. June 13, 1961 FOREIGNPATENTS 597,090 Canada Apr. 26, 1960

1. AN IMPROVED WAX COATING COMPOSITION WHICH COMPRISES ESSENTIALLY AREFINED PARAFFIN WAX PRESENT IN A CONCENTRATION FROM ABOUT 70 TO 90% BYWEIGHT, A FIRST OVERHEAD MICROCRYSTALLINE WAX PRESENT IN A CONCENTRATIONOF FROM ABOUT 8 TO 12% BY WEIGHT, SAID FIRST OVERHEAD MICROCRYSTALLINEWAX HAVING A CONGEALING POINT OF ABOUT 130* F., A 5% DISTILLATIONTEMPERATURE AT 10 MM. PRESSURE OF ABOUT 490*F. AND A 95% DISTILLATIONTEMPERATURE OF ABOUT 706*F., A SECOND OVERHEAD MICROCRYSTALLINE WAXPRESENT IN A CONCENTRATION FROM ABOUT 3 TO 12% BY WEIGHT, SAID SECONDOVERHEAD MICROCRYSTALLINE WAX HAVING A CONGEALING POINT OF ABOUT 182*F.,A 5% DISTILLATION TEMPERATURE AT 1 MM. PRESSURE OF ABOUT 509*F. AND A95% DISTILLATION TEMPERATURE OF ABOUT 659*F., AND A THIRD OVERHEADMICROCRYSTALLINE WAX PRESENT IN A CONCENTRATION OF FROM ABOUT 3 TO 7% BYWEIGHT, SAID THIRD OVERHEAD MICROCRYSTALLINE WAX HAVING A CONGEALINGPOINT OF ABOUT 136*F., A 5% DISTILLATION TEMPERATURE AT 1 MM. PRESSUREOF ABOUT 436*F. AND A 95% DISTILLATION TEMPERATURE OF ABOUT 661*F.